Price adjustment method and ex-dividend day returns in a different institutional setting

This article was published in the International Review of Financial Analysis [© Elsevier Inc.] and the definitive version is available at: http://dx.doi.org/10.1016/j.irfa.2015.05.005This study investigates the determinants of the ex-dividend day price behavior in the Athens Stock Exchange (ASE), a unique institutional setting, and examines how a major regulatory change in the price adjustment method affects the extent of the ex-day stock price drop. We find that allowing the market to freely adjust prices, after 2001, the ex-dividend day price improves the pricing efficiency of the market in the sense that the raw price ratio tends to one and abnormal returns tend to zero. We also find that in the absence of taxes on dividends and capital gains and certain microstructure impediments discussed in the literature - i.e., bid-ask spread, market makers, price discreteness, tick size and limit order adjustment mechanism - stock illiquidity is the best candidate for explaining the magnitude of the ex-dividend day price adjustment

Reticular Synthesis of HKUST-like tbo-MOFs with Enhanced CH₄ Storage

Successful implementation of reticular chemistry using a judiciously designed rigid octatopic carboxylate organic linker allowed the construction of expanded HKUST-1-like <b>tbo</b>-MOF series with intrinsic strong CH₄ adsorption sites. The Cu-analogue displayed a concomitant enhancement of the gravimetric and volumetric surface area with the highest reported CH₄ uptake among the <b>tbo</b> family, comparable to the best performing metal organic frameworks (MOFs) for CH₄ storage. The corresponding gravimetric (BET) and volumetric surface areas of 3971 m² g^–1 and 2363 m² cm^–3 represent an increase of 115% and 47%, respectively, in comparison to the corresponding values for the prototypical HKUST-1 (<b>tbo</b>-MOF-1), and are 42% and 20% higher than that of <b>tbo</b>-MOF-2. High-pressure methane adsorption isotherms revealed a high total gravimetric and volumetric CH₄ uptakes, reaching 372 cm³ (STP) g^–1 and 221 cm³ (STP) cm^–3, respectively, at 85 bar and 298 K. The corresponding working capacities between 5 and 80 bar were found to be 294 cm³ (STP) g^–1 and 175 cm³ (STP) cm^–3 and are placed among the best performing MOFs for CH₄ storage particularly at relatively low temperature. To gain insight on the mechanism accounting for the resultant enhanced CH₄ storage capacity, molecular simulation study was performed and revealed the presence of very strong CH₄ adsorption sites near the organic linker with similar adsorption energetics as the open metal sites. The present findings support the potential of <b>tbo</b>-MOFs based on the supermolecular building layer (SBL) approach as an ideal platform to further enhance the CH₄ storage capacity via expansion and functionalization of the quadrangular pillars

Reticular Chemistry at Its Best: Directed Assembly of Hexagonal Building Units into the Awaited Metal-Organic Framework with the Intricate Polybenzene Topology, pbz-MOF

The ability to direct the assembly of hexagonal building units offers great prospective to construct the awaited and looked-for hypothetical polybenzene (<b>pbz</b>) or “cubic graphite” structure, described 70 years ago. Here, we demonstrate the successful use of reticular chemistry as an appropriate strategy for the design and deliberate construction of a zirconium-based metal–organic framework (MOF) with the intricate <b>pbz</b> underlying net topology. The judicious selection of the perquisite hexagonal building units, six connected organic and inorganic building blocks, allowed the formation of the <b>pbz</b>-MOF-1, the first example of a Zr­(IV)-based MOF with <b>pbz</b> topology. Prominently, <b>pbz</b>-MOF-1 is highly porous, with associated pore size and pore volume of 13 Å and 0.99 cm³ g^–1, respectively, and offers high gravimetric and volumetric methane storage capacities (0.23 g g^–1 and 210.4 cm³ (STP) cm^–3 at 80 bar). Notably, the <b>pbz</b>-MOF-1 pore system permits the attainment of one of the highest CH₄ adsorbed phase density enhancements at high pressures (0.15 and 0.21 g cm^–3 at 35 and 65 bar, respectively) as compared to benchmark microporous MOFs

Reticular Chemistry and the Discovery of a New Family of Rare Earth (4, 8)-Connected Metal-Organic Frameworks with <b>csq</b> Topology Based on RE₄(μ₃‑O)₂(COO)₈ Clusters

In recent years, the design and discovery of new metal-organic framework (MOF) platforms with distinct structural features and tunable chemical composition has remarkably enhanced by applying reticular chemistry rules and the molecular building block (MBB) approach. We targeted the synthesis of new rare earth (RE)-MOF platforms based on a rectangular-shaped 4-c linker, acting as a rigid organic MBB. Accordingly, we designed and synthesized the organic ligand 1,2,4,5-tetrakis­(4-carboxyphenyl)-3,6-dimethyl-benzene (H₄<b>L</b>), in which the two methyl groups attached to the central phenyl ring lock the four peripheral carboxyphenyl groups to an orthogonal/vertical position. We report here a new family of RE-MOFs featuring the novel inorganic building unit, RE₄(μ₃-O)₂ (RE: Y³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺, and Yb³⁺), with planar <i>D</i>_2<i>h</i> symmetry. The rigid 4-c linker, H₄<b>L</b>, directs the in situ assembly of the unique 8-c RE₄(μ₃-O)₂(COO)₈ cluster, resulting in the formation of the first (4, 8)-c RE-MOFs with <b>csq</b> topology, RE-<b>csq</b>-MOF-1. The structures of the yttrium (Y-<b>csq</b>-MOF-1) and holmium (Ho-<b>csq</b>-MOF-1) analogues were determined by single-crystal X-ray diffraction analysis. Y-<b>csq</b>-MOF-1 was successfully activated and tested for Xe/Kr separation. The results show that Y-<b>csq</b>-MOF-1 has high isosteric heat of adsorption for Xe (33.8 kJ mol^–1), with high Xe/Kr selectivity (IAST 12.1, Henry 12.9) and good Xe uptake (1.94 mmol g^–1 at 298 K and 1 bar), placing this MOF among the top-performing adsorbents for Xe/Kr separation